Twelve-spotted skimmer (Libellula pulchella)

The twelve-spotted skimmer gains its common name from the twelve brown spots on its wings.

The wings of the twelve-spotted skimmer also feature white spots which develop with age.

The powder-like appearance on the thorax of the male twelve-spotted skimmer is known as ‘pruinescence’ and is a common feature among dragonflies.

The twelve-spotted skimmerhas yet to be classified by the IUCN.

The twelve-spotted skimmer (Libellula pulchella) is a large, striking dragonfly (3) which gains its common name from the twelve brown spots evenly distributed across its four wings (2) (4). The abdomen of the male is white-blue or grey and has a powder-like appearance (3) (5). The thorax is brown with two stripes on each side, which are grey above and yellow below (2) (3). As it ages, the stripes on the thorax of the male twelve-spotted skimmer become less distinctive (4).

The female twelve-spotted skimmer is similar to the male in appearance but has a brown abdomen and thorax, with continuous yellow stripes along each side (3) (5). Both the male and female twelve-spotted skimmer also have white spots between the darker spots on the wings (2) (4) (5), which develop with age (2). The eyes of both sexes are red-brown (4) The juvenile is similar in appearance to the adult female (2).

The twelve-spotted skimmer is common across the United States, southern Canada and northern Mexico (2). Throughout this range it is absent from certain areas in the far south and south-western United States (6).

The twelve-spotted skimmer is found around ponds, lakes and slow streams, where the water is often eutrophic and shallow (2) (4). Surrounding the edges of the water body there is usually plentiful vegetation, which is used by this species as a perch (3) (7).

The flight season of the twelve-spotted skimmer, when the adults are active, varies throughout its range (3). Activity usually occurs between late March and November (2) (4), but is most common between June and October (2).

The twelve-spotted skimmer is a highly territorial species, and the male defends its territory from other dragonfly species, as well as its own (2) (3). Conflicts are usually won by the individual with the greatest flight agility, and the winner gains a better territory or succeeds in retaining its original territory. Disputes are usually between males over areas which are frequently visited by females (2).

Reproduction in most dragonfly species is very similar, with the female flying into the male’s territory, and the male beginning to chase the female. The male will then grab the thorax of the female and form a mating wheel (2), which is a circular position formed by all dragonflies while mating (8). Copulation is brief and usually occurs during flight (3). The female then deposits the fertilised eggs into the water. The male keeps guard until the eggs are deposited as other males may attempt to mate with the female, which can displace the sperm from the previous mating (2).

The adult twelve-spotted skimmer forages from elevated areas such as the tips of tall weeds (2) (4), where it scans the air for small flying insects (2) (7). All dragonfly larvae are voracious predators and have extendable mouthparts with strong hooks to grip prey. The mouthparts retract to place the food into the mouth (8). The twelve-spotted skimmer larvae go through a series of developmental stages (7), eventually leaving the water body and metamorphosing into the adult form (8).

There are not known to be any major threats to the twelve-spotted skimmer at this time.

There are not known to be any specific conservation measures currently in place for the twelve-spotted skimmer.

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: arkive@wildscreen.org.uk

Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree (but not visibly in most spiders).

Eutrophication: a process in which a water body is enriched with excessive nutrients (such as nitrogen and phosphorus) resulting in the excessive growth of aquatic plants and the depletion of oxygen, creating unfavourable conditions for other organisms, such as fish.

Fertilisation: the fusion of gametes (male and female reproductive cells) to produce an embryo, which grows into a new individual.

Larva: immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.

Metamorphosis: an abrupt physical change from the larval to the adult form.

Territorial: describes an animal, a pair of animals or a group that occupies and defends an area.

Territory: an area occupied and defended by an animal, a pair of animals or a group.

Thorax: part of the body located between the head and the abdomen in animals. In insects, the three segments between the head and the abdomen, each of which has a pair of legs. In vertebrates the thorax contains the heart and the lungs.